(1) Field of the Invention
The present invention relates to a differential amplifier for audio-frequency linear amplification.
(2) Description of the Prior Art
A differential amplifier is used for amplifying an alternating current or voltage having an audio frequency. Therefore, the linear amplification characteristics are important.
A prior art differential amplifier comprises first and second transistors connected, via negative feedback resistors, to a common current source. In the prior art, since the emitter-base diodes of the transistors have logarithmic characteristics, the amplification characteristics are nonlinear, which is a disadvantage.